Electrical plug connecter



Aug. 11, 1931. A. H. CURTIS 1,818,926

ELECTRICAL PLUG CONNECTER Filed July 50, 1927 Ari/2W1? [drills Patented Aug. 11, 1931 ARTHUR HERBERT CURTIS, 0F IBEDFORD, ENGLAND ELECTRICAL PLUG- GONNECTER Application filed July 30, 1927, Serial No. 209,421, and in Great Britain August 5, 1926.

The invention relates to electrical plug connecters. The type of plug at present most commonly used for making semi permanent connections to socket bearing apparatus such for example as high tension batteries, have been found to suller from the effect that good contact is frequently not made between the plug and its cooperating socket. This is due in a large measure to the fact that the depths of the sockets vary considerably and also to the fact that the interior contact surface of the socket sometimes becomes coated with insulating compound, grease, or the like.

It has been proposed to overcomethe latter difficulty by the use of a substantially conical plug having a spirally disposed gripping edge, but the objection to this plug is that owing to its conical structure unless the socket is of the full and correct depth it makes very uncertain contact.

The object of the present invention is to provide a plug which shall overcome both the above difficulties in a simple manner and the invention consists broadly in the arrangement according to which the plug comprises a metallic strip with reduced end portions, said strip being bent upon itself so that said reduced end portions lie more or less parallel side by side and form the plug proper.

In order that the invention may be more clearly understood a plug in accordance with the invention will now be described, reference being made to the accompanying drawings, wherein Fig. 1 is a side elevation of said plug.

Fig. 2- is a sectional side elevation of the same.

Fig. 3 is a plan of the same.

Fig. 4 is an under plan of the same, and

Fig. 5 is a side elevation of a slight modification of the same.

Thus said plug comprises a strip of metal 1 bent to the form of a long rectangular U.

The strip is reduced for a space adjacent each of its two ends and the strip is bent so that the two reduced portions 1a thus formed lie closer together than the remaining portions of the arms of the U. These two reduced portions constitute the more or less parallel pieces above referred to. By pressing the arms of the U towards each other said reduced portions may be inserted of, and through this hole. from the inside I is passed a terminal screw 2 which screws into engagement with a terminal nut 3 of insulating material at the outside. The screw 2 is formed with a concentric through hole 2a and the outer end of the terminal nut 3 is formed with an outwardly expandingconcentric hole 3a somewhat larger than, and constituting a continuation of, said hole 2a. 7 I V It will thus be seen that the hole 2a constitutes a socket in electrical connection with the plug portions 1a so that a number of the plugsmay be plugged one on top of the otheiz. The head 22') of the terminal screw 2 may be rectangular and adapted to f as and a clean metallic surface is available for contact.

If desired a shroud of an insulating material, capable of being produced in different colours may be interposed between the terminal nut 3 and the U strip 1, as shown at 4 of Fig. 5, said shroud being also bent to fit the exterior periphery of said bent strip or the arms and portion 1?) may be coated with an insulating enamel of distinctive colour so as to provide an insulating surface by which the plug may be held.

It will be understood that the construction may be varied in a number of ways without departing from the scope of the invention as defined in the appended claims. For example the part of the metallic strip lying between the reduced ends may be more or less circular instead of U shape.

\Vhat I claim and desire to secure by Letters Patent is 1. An electricalplug connecter, comprising a metallic spring strip doubled upon itself in U-form to provide separated side portions, said separated side portions having relatively wide finger grip sections adjacent the bend of the U and narrow reduced end portions to enter a contact socket when the side portions are pinched together by means of the finger grip sections aforesaid and a terminal screw extending. through the connecting portion of the strip between the side portions, said terminal screw being of tubular form to provide a socket for the insertion of another similar plug connecter therein.

2. An electrical plug connecter, comprising a metallic spring strip doubled upon itself in U-form to provide separated side portions, said separated side portions having relatively wide finger grip sections adj acent the bend of the U and narrower reduced end portions to enter a contact socket when the side portions are pinched together by means of the finger grip sections aforesaid, a tubular terminal screw on the connecting portion of the device between the side portions thereof and an insulating finger grip also on said connecting portion.

3. An electrical plug connecter, comprising a metallic spring strip doubled upon itself in U-form to provide separated side portions, said separated side portions having relatively wide finger grip sections adjacent the bend of the U and narrower reduced end portions to enter a contact socket when the side portions are pinched together by means of the finger grip sections aforesaid, a tubular headed contact screw extending up through the connecting portion of the strip between the side portions thereof and an insulating button threaded on the upper extended portion of the tubular screw.

4. An electric plug. connecter, of substantiall-y U-form and having? a substantially rec- ARTHUR HERBERT CURTIS. 

